Parallel Robots with Adaptronic Components

Performance in high-speed mechanisms can be increased by means of a lightweight design. But, quite often, the resulting structures have the drawback of being susceptible to vibrations. This can be overcome by applying a smart-structures technology. In this work, an application to parallel mechanisms is presented, in which undesired vibrations are reduced by integrated piezoceramic (PZT) actuators and sensors, which are driven by a proper control system. As a basis for the development of suitable control laws, a proper simulation approach is to be used which is capable to model the mechanism’s dynamic behavior correctly, taking into account large motions. The multibody approach fulfills these requisites. The paper deals with the development of a fast C++-coded S-function in MATLAB/SIMULINK for a “five revolute joint” mechanism chosen as a test platform. This routine incorporates a multibody model with changing states. The flexibility of the bodies is taken into account in a modal form. The corresponding parameters are read from data files which can be generated by suitable preprocessors of proprietary multibody software packages like SIMPACK. The created model is compared with an equivalent SIMPACK-model and an interpolation-based control strategy is discussed.